That one dude...
Why should I have a faith?
What is "all the way up" and "all the way down?"
'Turtles all the way down' refers to a story in which someone rejects science and holds to their belief that the world rests on the back of a turtle. When asked what the turtle stands on, they reply a larger turtle. When asked what the bottom turtle stands on, they say it's turtles all the way down.
Your question about whether or not a god could have a god seemed like a similar notion in reverse. Taking for granted that there is a god, who's to say if that god has a god who has a god who has a god...etc.
No, you have situations where it is an 'unknown'. Now, I personally do not subscribe to the 'every possibility', aspect of the original premise, but that's sort of besides the point
Every possibility is the entire point. If there's a mulltiverse, what possibility doesn't exist?